"We will have more boots on the ground closely scrutinizing and monitoring production and manufacturing activities," FAA Administrator Mike Whitaker will tell lawmakers. "We will consider the full extent of our enforcement authority to ensure Boeing is held accountable for any non-compliance."

The FAA, acting after a cabin panel blew out during flight on a new Alaska Airlines MAX 9, took the unprecedented action of barring Boeing from expanding production of its 737 MAX until it addresses quality issues.

The FAA grounded 171 MAX 9 jets on Jan. 6, resulting in thousands of flight cancellations by Alaska Airlines and United Airlines. The grounding was lifted on Jan. 24 and the agency said Monday 94% of the jets have returned to service.

Lawmakers on a U.S. House aviation committee last week asked Whitaker to answer whether the agency has found "any evidence of persistent quality control lapses in any of Boeing's production lines."

The FAA, which did not have a permanent administrator for 18 months until Whitaker's 98-0 confirmation, has come under growing scrutiny after a series of potentially catastrophic near-miss aviation safety incidents, persistent air traffic control staffing shortages and a January 2023 pilot messaging database outage that disrupted 11,000 flights.

The agency says it will audit all elements of production at Boeing and fuselage production at Spirit AeroSystems and reexamine the long-standing practice of delegating some critical safety tasks to Boeing.

The FAA has scrutinized Boeing's quality and other issues in recent years as it faced harsh criticism for its actions in the run-up to the MAX certification.

In March, the FAA said it had boosted staff providing regulatory oversight of Boeing to 107 from 82 in previous years.

In 2021, Boeing agreed to pay $6.6 million in penalties after failing to comply with a 2015 safety agreement.

(Reporting by David Shepardson. Editing by Gerry Doyle)

By David Shepardson